Hydraulic press



Sept. 2 1924. 1,506,903

' P. HANSEN HYDRAULI C PRES 5 Filed Dec. 16, 1922 a 1; HJHI 10 7 [l .1

avwentoz Patented Sept. 2, 1924.

UNITED STATES PATENT OFFICE.

.POUL HANSENJOF HELLERUP, NEAR, COPENHAGEN, DENMARK, ASSIGNOR TO F. L.SMIDTH & COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

HYDRAULIC PRESS.

Application filed December 16, 1922. Serial No. 607,462.

To all whom it may concern:

Be it known that I, PoUL HANSEN, a subject of the King of Denmark,residing at 11 Rebekkavej, Hellerup, near Copenhagen, Denmark, haveinvented certain new and useful Improvements in Hydraulic Presses, ofwhich the following is a specification, reference being had to theaccompanying drawing, forming a part hereof.

This invention has been developed with especial reference to itsapplication to presses designed for use in the formation of sewer pipes,drain pipes, etc., from clay, which is forced by a plunger through asuitable die or former. It will be seen, however, as this descriptionproceeds, that the invention is independent of the particular use towhich it is applied and that presses which embody the invention can beused for other purposes than that indicated. In the apparatus which hasbeen chosen for illustration as an embodiment of the invention thepipe-forming plunger is carried by the piston of the press and water orother suitable liquid is supplied to the cylinder of the press, at eachend thereof, from a constantly operating pump,

preferably a centrifugal pump, the number of revolutions of the pumpbeing kept constant while the quantity of water delivered in a unit oftime is varied as the conditions of operation require. Provision is madewhereby the movement of the piston and therefore of the plunger of thepress can be controlled at the will of the operator, while the piston isbrought gradually to rest at either extreme of its movement without necessitating action on the part of the operator. The invention will beexplained more fully hereinafter with reference to the accompanyingdrawing in which it is illustrated and in which- Figure 1 is a viewpartly in vertical section and partly in elevation of a press whichembodies the invention.

Figure 2 is a detail view in section showing a portion of the cylinderand the piston with its check valves.

Figure 3 is a detail view showing a portion of the piston in sectionwith its check valves.

In the embodiment of the invention illustrated in the drawing, acentrifugal pump 1, of any suitable construction, is connected on itssuction side, as by the pipe 2, with the discharge outlet 10 of thecylinder 6,

and on its delivery side, as by a ipe 3, withthe intake of the valvechest 4:. .he plunger 5*, which co-acts with the pipe-forming cyl inderor die 5, in the usual manner, is car ried by rods 5 which are securedto the piston 15 and are extended through suitable stuffing boxes in thehead of the cylinder, both ends of which are closed. The valve chest 4is connected with the respective ends of the cylinder '6 throughchannels 8 and 9 which terminate in the Wall of the cylinder in taperedor heart-shaped ports as shown at 18 in Figure 3. Within the valve chest4: is a slide valve 7 the ends of which are arranged to lap the outerends of the channels 8 and 9, while the recess 7 in the working face ofthe slide valve is adapted to place one or the other of the ports 8, 9,as the case may be, in communication with. the chamber 10 of thedischarge port 10. For convenience in operation the stem 11 of the slidevalve 7 is connected by a link 12 with one arm of a bell crank lever 13provided with a handle 14.

The piston 15 does not itself lap the ports 18 of the channels 8 and 9in the extreme positions of the piston but is provided with pivotedcheck valves 16 on its upper and lower faces which respectively lap thechannels 8 and 9 in the extreme positions of the piston, such checkvalves moving freely to permit the delivery of water into the cylinder,as indicated by broken lines in Figure 2, but moving to closed position,as shown by full lines in Figure 2 under the influence of the Water asit is discharged from the cyl inder at one end or the other, as the casemay be.

In describing the operation of the press it will be assumed that thepiston 15 is at the beginning of its forward stroke, the slide valve 7having been moved by the operator so as to place the delivery side ofthe pump 1 in communication with the upper end of the cylinder 6. Themovement of the piston can be checked at any time, if desired, bymovement of the slide valve 7, but the piston will be gradually broughtto rest as 1t approaches its extreme position without the attention ofthe operator by reason of the fact that the valve 17 on the forward faceof the piston, as the piston approaches the limit of its forwardmovement, will lap the port of the channel 9, thereby gradually cutting03 the return of water from the forward end of the cylinder to theintake of the pump 1.

' In the upward or return movement of the piston, initiated by propermovement of the slide valve 7, the u per check valve 16 ,will in likemanner gra ually cut off the return of water from the upper end of thecylinder to the pump and gradually bring the piston to rest.

It will be 'seen that the pump 1 is permitted to operate continuously,the delivery of water to the press cylinder being controlled either bycutting off the inflow, at the will of the operator, or by cutting ofithe return of water to the suction side of the pump by the automaticaction described. It will further be observed that although the forwardmovement of the piston may be slow, as determined by the resistance, thereturn movement of the piston will be rapid.

It will be understood that various changes in details of constructionand arran ement can be made to suit difi'erent conditlons of use andthat the invention, except as pointed out in the claims, is not limitedto the particular construction shown and described herein.

' November, A. D. 1922.

der, a piston, an hydraulic pump, means whereby the discharge of thepump can be connected to either end of the cylinder, and the suction ofthe pump can be connected to the other end of the cylinder, and checkvalves carried by the piston on opposite faces and adapted to cut oficommunication between the cylinder and the pump at the corresponding endas the piston approaches the limit of its stroke in either direction.

2, In a press, the combination of a cylinder having a valve chest withchannels opening in the cylinder wall at the respective ends, and anexhaust chamber, an hydraulic pump having a connection on the dischargeside to the valve chest and on the suction side to the exhaust chamber,a valve to control the connections between the valve chest and exhaustchamber on one hand and the respective ends of the cylinder on the otherhand, a piston, and check valves carried by the piston on opposite facesto close the corresponding port in the wall of the cylinder as thepiston approaches the limit of its stroke in either direction.

This specification signed this 29th day of POUL HANSEN.

